Congrats Number 9!
So all i have to do is a light low pressure rinse to get the rail dust off?

That loosened the dirt/rail dust... then he used light, straight, one direction strokes with soapy water and a soft sponge.... then lightly rinsed and clay barred. The clay bar is what really gets the the junk off, with the preceding steps breaking/loosening/removing the surface dirt.